A molecular phylogenetic study of the Drepanoidea based on the EF-1α sequences and combined EF-1α and COI sequences was carried out in order to infer higher classification at and above the subfamily level. The sample contained 14 taxa representing 13 genera recognized in the Drepanoidea. The results revealed that the Drepaninae, Thyatirinae and Cyclidiinae respectively form monophyletic groups. The sister relationship between the Drepaninae and the Thyatirinae was validated. The monophyly of the Cyclidiinae with the Drepaninae+Thyatirinae was supported robustly. Hypsomadius insignis and Oreta vatama within the traditional definition of the Drepaninae formed an individual clade with robust support (100%) and constitutes a sister relationship to a clade containing the rest of the Drepaninae in all the topologies, which means that the subfamily Oretinae of the Drepanidae should be restored. The family Drepanidae is divided into four subfamilies: Drepaninae, Oretinae, Thyatirinae and Cyclidiinae in this work. The family Epicopeiidae formed a monophyly with high bootstrap values. The result of combined analysis of EF-1α and COI showed that the Epicopeiidae have a closer phylogenetic relationship with the Geometridae than with the Drepanidae and belong to neither the Drepanoidea nor the Geometroidea.

The effects of the chitin synthesis inhibitor triflumuron, 2-chloro-N-[[[4-(trifluoromethoxy)phenyl]amino]carbonyl]benzamide, on the housefly, Musca domestica Linnaeus were examined in the laboratory. A dose of 1 μg of triflumuron applied topically to adult females of M. domestica resulted in egg hatch inhibition greater than 95%. At doses below 1 μg applied topically to adult females, subsequent hatched larvae were also highly sensitive to triflumuron; 0.5 μg applied topically produced 25% inhibition of egg hatch, but of the larvae that eclosed, only 20% survived to pupation. Hence, a dose of 0.5 μg applied to adults gave a total mortality of 85%. The effects of a single topical application of triflumuron declined over time in a dose dependent manner. After a dose of 1 μg, <5% of the first egg batch hatched, however, after 14 days egg hatch had risen to >90%. Topically applied triflumuron was most effective in inhibiting egg hatch when applied to females less than 3 days old. After 60 min tarsal contact with 20% triflumuron suspension concentrate on poly cotton cloth, 100% egg hatch inhibition was maintained for up to 1 week. Lower contact times, or triflumuron concentrations, gave lower percentage mortalities. The results suggest that triflumuron has considerable potential as a control agent for incorporation into autosterilizing devices for housefly control. However, further work is required to develop delivery systems capable of transferring an effective dose to females under field conditions.

Various substances have been used by different workers as substrata for breeding the house-fly under laboratory conditions. Horse manure was recommended by Hutchison (1916), Glaser (1924), Grady (1928), Derbeneva (1935) and Kusina (1936). A mixture of horse manure and hog manure was used by Hockenyos (1931). Feldman-Muhsam (1944) obtained the best breeding results by using cow dung. Pig dung was preferred by Lörincz & Makara (1935). Lodge (1918) reared house-flies on a mixture of casein, bread, water and banana. Richardson (1932) used another mixture of wheat bran, alfalfa meal, diamalt, yeast and water. Kobayashi (1935) used a by-product of soya beans. Basden (1947) in his large scale experiments, necessitating about 2,500 flies daily, used a mixture of middlings, grass meal, tap water, dry malt extract and dried yeast.

Diclidophlebia eastopi Vondráček and D. harrisoni Osisanya are pests of the timber tree Triplochiton scleroxylon in Nigeria. The egg and five nymphal instars are described and illustrated. Under laboratory conditions the life-cycle (egg-egg) of D. eastopi was completed in 18½ days, and mated fed females had a life span of 15 days. The sex ratio in the field was 1:1. Nymphs feed near the veins of mature leaves, causing premature leaf fall; adults feed on leaves of any age and cause no symptoms. Fecundity averaged 502 eggs, with a daily oviposition rate of 38; most eggs are laid in batches along the veins of mature leaves. The life-cycle of D. harrisoni was 16 days; mated and fed females lived 10 days. The feeding of firstinstar nymphs near the margins of young leaves causes leaf tunnels to form, inside which the nymphs complete their development; adults feed only from young leaves. In the field the female:male ratio was 2:3. Fecundity averaged 131, with a daily oviposition rate of 31. Fertility improved with multiple matings. The eggs are laid singly, partially embedded in the epidermis, and only on young leaves.

A description is given of some of the developmental stages of Sosylus vicinus (Grouv.), S. silius Hinton and S. reflexus Pope from Papua New Guinea. At least three instars are recognised in all species, and the first or primary instar is of the triungulin type. A triungulin is also reported as the primary instar of another colydiid, Asosylus rhysodoides (Pasc.). This is the first time triungulins have been found in the coleopterous family Colydiidae. Differences in the triungulin of the three species of Sosylus are recognised, based on the form and arrangement of segmental spines. The structure of the different instars with regard to their habits on the host is discussed, and a brief comparison is made with larvae of Meloidae and Rhipiphoridae, the only two other families of Coleoptera with triungulin first-instar larvae.

Using several methods, claims that stem-borers, especially Scirpophaga incertulas (Walker), cause serious crop loss in deepwater rice were tested in Bangladesh. Insecticides were used to control different borer broods. Early season, pre-flood applications reduced infestation, but did not affect yield. One to three mid- to late-season applications of monocrotophos at 250 g a.i./ha significantly reduced infestation and/or whitehead numbers, with yield savings (7-10%) similar to those which earlier workers obtained by applying diazinon 20 times in a season. In each of six years, tiller populations peaked before flooding, then steadily declined until harvest, but stem-borer infestation varied, remaining low until late season in two of the years. In 1981, infestation lower than 24% pre-flood and 42% at harvest did not affect yield. In 1982, eighty-four correlation calculations showed no consistent significant effects of infestation (27-60%, C.V. 40%) on yield (25 000 stems were dissected). Anatomical studies of elongated stems revealed S. incertulas feeding neither causes significant structural damage nor seriously interrupts nutrient flow; also, the passage of a larva through a nodal septum is not detrimental. Irrespective of stem-borer attack, the submerged lower internodes commonly die, the fibrous remains anchor the upper stem, and nodal roots take over nutrient uptake. Studies of panicle-bearing stems (n = 838) showed that, even with 97% stem infestation, most yield loss results from infestation of the terminal internode and is manifested predominantly as whiteheads. In a specific study, 94% whiteheads (n = 205) were associated with terminal internode infestation, where larval feeding in the narrow stem had disrupted food conduction, so preventing grain-filling. The apparent tolerance of S. incertulas by deepwater rice varieties is consistent with their being a primitive group of cultivated rices.

By the method of attacking flying swarms of locusts with insecticides sprayed directly into the swarm by relays of light aircraft, a proportion of the swarm receives a sub-lethal dose from each sortie. For successful operation it is essential that a substantial contribution to the final mortality should be produced by the accumulation of these sub-lethal doses on individual insects over a period of time. The object of the present experiments was to determine whether such doses applied at intervals are wholly additive in their effects. The poison used was dinitro-o-cresol (Mk. IV DNC solution) and to shorten the experimental procedure, the locusts, Schistocerca gregaria (Forsk.) and Locusta migratoria migratorioides (R. & F.), were dosed by means of a single drop of poison applied to the ventral surface of the abdomen by a micro-drop syringe.

When locusts are given regular daily doses of DNC the doses are not wholly cumulative in their effect. After the second or third day the lethal effect of each dose becomes steadily less, and after the fourth or fifth day it tends to zero, representing a steady state in which the rates of application and loss of insecticidal activity in the survivors are equal.

When the dose is applied in two halves with various time intervals between them, the cumulative effect during the first 24 hours is less in S. gregaria than in L. migratoria. In the latter species it is possible that sensitisation occurs. After three days, the first half-dose has fallen to an estimated 20 per cent, of its initial effectiveness in each species.

These two species are equally susceptible to a single dose expressed as μg. DNC/g. body weight. The females are more resistant than the males to daily doses (relative susceptibility in S. gregaria, 1·54) but probably not to single doses (relative susceptibility, 1·09).

Resistance to a daily dose correlates roughly with resistance to a single dose, the total dose required to produce 50 per cent, mortality in four days being about twice the LD50 for a single dose.

If flight activity does not materially alter the present results, it is evident that the non-cumulative effects of sub-lethal doses could cause a serious loss in the efficiency of an air-spray operation if it were unduly prolonged. Thus a quantity of insecticide sufficient to kill over 99 per cent, of the locusts if applied as a single dose would kill less than 40 per cent, if the application were spread over four days.

Egg Parasites.—In the Eastern Transvaal, Swaziland and Natal the eggs of Heliothis armigera are parasitized by Trichogramma luteum, Gir., and Telenomus (Phanurus) ullyetti, Nixon. No other egg parasites have been encountered.

Representative samples of eggs were collected weekly or twice-weekly over a period of seven years and over wide areas from the various cultivated crops and colonies of wild food-plants which exemplify the annual chain of breeding sites of H. armigera. The collected eggs were incubated to determine the “active” fraction derived after withdrawal of the infertile portion and of eggs exposed for less than 24 hours to parasite action. Observed parasitism was computed against the “active” eggs and is regarded as an index of the parasitism in the field. Running indices of this nature are given graphically to indicate the annual incidence of egg parasitism in percentages, which may be viewed in relation to the incidence of bollworm as evinced by oviposition data in the figures given. Sustained high levels of parasitism are associated mainly with the more abundant egg populations on winter-irrigated vegetable crops grown between July and November.

It has been found that Telenomus occurs mainly in the period August to December, and Trichogramma in the period December to March–April. The high parasitism of the winter egg populations is due, therefore, almost solely to Telenomus.

Evidence is submitted that the levels of parasitism in certain crops are commonly much higher than in others. Explanations are suggested by consideration of sites of egg deposition, accessibility of eggs, plant habit, vegetative and flowering, and, particularly, the known oviposition-flowering relationship of Heliothis moths. The latter has an important bearing on the persistence of host material and governs opportunity for the intervention of parasite progeny in increasing numbers.

Records on the status of egg parasitism have been taken in conjunction with investigations of the extent of larval mortality associated with the various types of crop. The rôle of egg parasites as agents reducing the issue of moths from winter and spring breeding areas is discussed briefly. Comparisons are given to show that the influence wielded is inappreciable even in some cases where parasitism is particularly high.

The coconut scale, Aspidiotus destructor Sign., was recorded for the first time from the island of Principe in November 1954, but it is practically certain that it was actually introduced accidentally in 1952.

Prior to 1954, normal fluctuations had occurred in the total annual production of copra of the island, probably correlated mainly with rainfall conditions. However, in 1954 there was a steady and very serious decline in production due to damage caused by Aspidiotus. Several species of endemic natural enemies were found attacking the scale, but the control exerted by them was quite inadequate to prevent astronomical increase of Aspidiotus.

The insecticidal activities of 13 triphenyltin compounds having the general formula (C6H5)3Sn X were compared with those of other organotin compounds and DDT by exposing adults of Sitophilus oryzae (L.) for 48 hours on filter paper impregnated with 1 per cent, solutions of the compounds in benzene, and by allowing larvae of Tineola bisselliella (Humm.) to feed for 14 days on pieces of woollen cloth impregnated with 1 per cent, by weight of the compounds. The triphenyltin compounds were ineffective as contact insecticides, virtually all the Sitophilus adults surviving, whereas all were killed by DDT. Their effectiveness as stomach poisons varied with the nature of the Group X, mortality after 14 days amongst the Tineola larvae ranging from 76 per cent., for triphenyltin thiophenoxide, down to zero, for hexaphenylditin. All except the latter and triphenyltin sulphide were highly effective moth-proofing agents, the weight lost by the test pieces being less than 5 per cent, of that lost by the untreated control. Tetraphenyltin afforded no protection against Tineola, but tributyltin oxide caused 100 per cent, mortality, apparently by contact action, since none of the test piece was eaten.

The genus Diabrotica includes a large number of pest species, including some of the most important crop pests of the Americas. The parasitoid Centistes gasseni Shaw is the first braconid to be described parasitizing Diabrotica in South America, and high natural infestations are reported. Field and experimental observations on the host range, distribution and biology of this parasitoid are described. Centistes gasseni was collected in southern Brazil, eastern Paraguay and northeastern Argentina, in a region comprising humid lowlands and highlands, and cool temperate to warm subtropical climates, with regular rainfall in excess of 1300 mm. Three Diabrotica species, D. limitata (Sahlberg), D. speciosa (Germar) and D. viridula (Fabricius) were found to host the parasitoid, with mean percent parasitism of 5.4, 2.0 and 1.0%, respectively. Diabrotica speciosa and D. viridula are the two most important pest Diabrotica species in South America. Laboratory experiments with field-collected beetles and parasitoid cocoons indicated that C. gasseni overwinters in adult host beetles, remaining dormant in its live host below developmental temperatures. A potential distribution of C. gasseni in North America is proposed based on its known climatic range and the distribution of the main pest species of adult overwintering North American Diabrotica.

In arabica coffee estates at Kahuguni and Magogoni, Kenya, female giant looper moths, Ascotis selenaria reciprocaria (Wlk.), rested on coffee tree stems at 60·7 ± 9·8 cm above ground and males at 65·7 ± 6·6 cm; most eggs were laid less than 122 cm above ground. In the laboratory, females laid on average 693 eggs in 5·3 batches; peak oviposition and fertility were 2–3 days after emergence. Life span was 8·3 days for females and 10·4 days for males; at death females contained 1·4 spermatophores each (1·1 in field-collected specimens). It is concluded that hand-picking of moths will have little control value unless done the day after emergence, but that tree-banding with residual insecticide 122–130 cm above ground would kill 90% of the emerging larvae.

The sugarcane borer, Diatraea saccharalis (F.), has a widespread distribution throughout the Western Hemisphere and is a pest of many crop plants including sugarcane, corn, sorghum and rice. The use of Bacillus thuringiensis (Bt) corn has been the primary tool for managing this species in corn fields. Sugarcane borer control has been recently threatened by observations of susceptibility and/or resistance to certain varieties of Bt corn and the protein used in many newer varieties. This has led to increased interest in understanding sugarcane borer genetic diversity and gene flow within and among its populations and the consequent exchange of alleles between geographically distant populations. The objective of this study was to examine reproductive compatibility between host-associated geographic populations of D. saccharalis in Argentina and to determine whether this pest represents a complex of host-associated cryptic species rather than a wide ranging generalist species. Intra and inter-population crosses revealed that D. saccharalis populations from the northwestern and Pampas regions presented evidence of prezygotic and postzygotic incompatibility. Such a result is likely to be the product of an interruption of gene flow produced by either geographic or host plant associated isolation, suggesting that Tucumán (northwestern) and Buenos Aires (Pampas) populations of D. saccharalis are a distinct genotype and possibly an incipient species.

Crosses of Sudanese strains of Anopheles arabiensis Patt. resistant and susceptible to malathion indicated that the resistance was incompletely dominant. The results of tests of male progeny of successive backcrosses agreed well with the hypothesis of control of the resistance by a single gene. However, the results from females suggested the additional involvement of a sex-limited modifier. Tests of mixtures initiated with a 1:1 ratio of resistant and susceptible first-instar larvae gave little evidence for selective mortality during the larval stage. However, the mortalities in tests on malathion recorded among adults emerging on successive days from these mixtures, and also from F2 and backcross progenies, indicated that the development of the resistant larvae was significantly faster than that of the susceptible ones. The fact that this occurred in the F2 and backcross progenies indicates that it may be due to a pleiotropic effect of the resistance gene, but it is pointed out that results from much more prolonged backcrossing would be necessary to rule out the possible effects of linked genes.

The geographical ranges of Sahlbergella singularis and Distantiella theobroma overlap, and the Gold Coast lies in the zone common to both. The respective northern limits remain to be determined, and should be investigated to the north of the main cacao belt, from Kintampo to the Afram plain.

The same area should also yield information on the possible importance of alternative hosts in the dispersal of cacao Mirids, as the small stands are well separated from each other.

Earlier records, that D. theobroma is confined to seedlings and S. singularis to mature trees, are erroneous. D. theobroma is found on pods and, particularly, chupons. The feeding range of S. singularis includes fan branches in addition, but breeding is confined to chupons and pods.

Observations suggest that there is competition for breeding sites on chupons. Of the many chupons in an area only a small number is available to Mirids, and the proportion of nymphs reaching maturity is limited by their sedentary habit and the destructiveness of their feeding.

Co-existence of the two species is possible by their slightly different habits. S. singularis produces more eggs, but is more diffusely distributed. D. theobroma is virtually restricted to chupons, but can quickly build up a large population in favourable areas by its greater rate of egg production.

In Nigeria, the rate of egg production by D. theobroma is less than that by S. singularis, and this, together with the sparsity of chupons, may account for the unimportance of D. theobroma in that country.

Dispersal of the larvae of the cattle tick Boophilus microplus (Can.) was studied in connection with problems of controlling and eradicating this pest and bovine babesiosis in New South Wales. Larval ticks were recovered by pressing flannelette-covered boards on to the pasture or litter surface, or sampling with cattle. Many of these larvae were capable of completing parasitic development.

Strong winds were an important factor in determining the distance travelled, as the longest journeys in pasture were for the most part in the directions in which the larvae would have been carried by recorded strong winds. Much of the dispersal is accomplished when larvae are transferred from one grass blade to another moving in the wind, but a great number of airborne larvae were captured on tanglefoot-covered traps. Movement by wind was clearly demonstrated over short pasture, up to 100 ft and possibly as far as 260 ft from the point of hatching. In long grass one larva travelled 83 ft, but in scrub and forest the greatest distance travelled was 15 ft. Many larvae that travelled long distances were capable of completing development on cattle.

Tick larvae could be transported by casual hosts and then dropped in a viable condition. A horse carried larvae for 900 ft, a rat and cockerels 100 ft, a magpie in flight 600 ft, and a pigeon in flight half a mile. A horse dipped six days earlier in ethion dropped live and viable larvae after transporting them 150 ft.

Security has been improved against the movement of larvae from the Cattle Tick Research Station, Wollongbar, New South Wales, to neighbouring properties, and from Queensland into New South Wales, by widening existing buffer zones to 330 ft. Inspectoral staff are now required to spray themselves and their horses before re-entering New South Wales from the buffer zone.

Two field experiments examined the effect of dung fauna on the breeding success of Haematobia irritans exigua DeMeijere at Rockhampton, Australia, and Haematobia thirouxi potans (Bezzi) at Hluhluwe Game Reserve, Republic of South Africa. Dung pads naturally infested with Haematobia eggs were produced by cattle at Rockhampton and by Cape buffalo at Hluhluwe. Pads were either exposed to, or protected from, all dung fauna for various periods up to four days. The effect of dung fauna on the immature stages of Haematobia spp. was estimated from differences in the numbers and size of flies that emerged from treated and control pads. In the first experiment, pads produced during the morning and afternoon were exposed for one, two or four days on seven different occasions. At Rockhampton, fauna-induced mortality was substantial but did not increase significantly after the pads had been exposed for one day. At Hluhluwe, in pads produced during the morning, fauna-induced mortality rose substantially with duration of exposure; in afternoon pads the increase was not statistically significant. Fly size, indicated by the mean headcapsule width of surviving females, decreased as exposure of pads to dung fauna increased from zero to four days, except in the afternoon pads at Rockhampton. In the second experiment, pads produced in the afternoon were exposed in the field for four days on 16 occasions at Rockhampton, and on 17 at Hluhluwe. Fauna-induced mortality averaged 79% and 84%, respectively. The activities of the dung fauna reduced the headcapsule widths of surviving flies by an average 2% at Rockhampton and by 7% at Hluhluwe, despite similar levels of dung dispersal. The dung fauna associated with the highest mortality of H. irriatans exigua at Rockhampton were Scarabaeinae and Macrocheles spp., while there were no significant associations between fly mortality and particular fauna in the Hluhluwe data.

The theory that the larger wild mammals, commonly called “big game,” are solely and entirely responsible for the presence of tsetse-flies, has become so firmly fixed in the mind of the average “man in the street” in South Africa, that no amount of contrary argument or even proof, were such forthcoming, could ever have much effect in altering his opinion. The newcomer quickly assimilates the same idea, and after a time begins to voice it as assertively as his mentor. It is thus most difficult to obtain really reliable data. An investigator, beginning an enquiry with an open mind, finds himself flooded with such a mass of apparently well substantiated statements, provided by experienced and obviously sincere persons, that he can with difficulty keep his mind free from a certain amount of bias. Starting from the assumption that the presence of fly depends upon that of game, arguments against the continued existence of the latter quickly multiply in the public mind. I was talking to a friend the other day, and he mentioned that he had been replying to some questions upon this very subject. He was no partisan of the anti-game movement, but regretfully expressed his conviction that in order to get rid of tsetse-fly it would be necessary to abolish the larger animals. I ventured, to ask for some clear instance of this interdependence. He was unable to quote any first-hand evidence which might not have been explained away, and his main contention, in short, was, “Of course the fly is dependent upon the game, everyone with any experience knows that; ask any old hunter or native.” This, I think, about sums up the ideas of the majority of people, and, if further argument is deemed necessary, the assumed general disappearance of the fly after rinderpest is pointed to as affording conclusive proof. The presumption is, of course, that the fly, deprived of its means of subsistence, died of starvation. An acquaintance with some of the districts visited by the epidemic would however by no means indicate that this was the real cause of the phenomenon, where it occurred. A study of the effect of rinderpest upon the relations between fly and game, might indeed, were it possible always to obtain accurate data, shed some new and interesting light upon the whole subject.

Using a deterministic model of a tsetse population, theoretical calculations have been made of the effect of repeated applications of a non-persistent insecticide upon a natural population. It has been assumed that the insecticidal applications instantaneously reduce the adult population, and that there is no residual effect.

For the numerical work it has been assumed a female fly has a pupal period of four weeks and an average expectation of life of six weeks and produces her first larva three weeks after emergence, and subsequent ones at intervals of one-and-a-half weeks.

Results have been calculated for kills of females varying from 50 per cent, to 95 per cent, per application, for series of up to eight successive applications, and for intervals between successive applications of from one to six weeks and also for the case when the population is allowed to become stable between applications.